05:05-02

Issue 1 en

Opticruise

Description of operation and work description

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100 830

© Scania CV AB 1995-10
1 585 369
 Contents

General Opticruise in brief ..............................................3

Introduction ........................................................4
Controls and operation .......................................6

Description of operation Gear changing ....................................................7

Opticruise controls the engine via EDC ............ 7
Gear changing sequence, description ................ 8
Engine brake program ....................................... 9
Starting gear, programming .............................. 9
Kick-down ..........................................................9
Auxiliary brake system ......................................9

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EDC cruise control .......................................... 10
ABS/TC ............................................................10
Power take-offs ................................................10
Configuration, control unit .............................. 11
Power supply and fuses ................................... 11
Interaction with other systems ........................ 12
Opticruise, design .............................................14
Warning system ................................................16

Fault codes General .............................................................19

Faults that do not generate fault codes ............ 19
Clarifications, new terms ................................ 20
List of fault codes ....................................... 19-52

Electrical system References to wiring diagrams ........................ 53

Location of electrical components ............. 54-55
Control unit signals .................................... 56-59
Driving mode selector ......................................60

Test program .............................................. 61-71

Mechanical work General .............................................................73

Instructions for repair and adjustment ....... 73-76

Exploded view drawings Components on gearbox ............................. 77-83

2 © Scania CV AB 1995 05:05-02 en

 General

General

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Opticruise in brief
Opticruise is a system which allows a normal Opticruise requires that the vehicle be fitted
manual gearbox to shift automatically. The with both EDC and ABS/TC, due to the infor-
clutch is retained but is used only when start- mation exchange requirements between the
ing, stopping and shunting. systems.
A control unit collects and processes data from When changing gear, the engine speed is con-
controls, sensors and adjacent systems such as trolled so that the speeds of the gearbox input
EDC, ABS/TC and auxiliary brake (if fitted). shaft and output shaft correspond for the gear
to be engaged. Gear changing is only then
When it is time to change gear, the control unit completed.
actuates the solenoid valves, releasing com-
pressed air to the air cylinders. These air cylin- When necessary, the exhaust brake is used to
ders then change to the required gear. make changing up fast and smooth.
The control unit has an in-built warning sys-
tem. Fault codes can either be read on the dis-
play or using a PC and the Scania Diagnos
program. The latter makes fault diagnosis
quicker.

05:05-02 en © Scania CV AB 1995 3

General

Introduction Scania Opticruise is an automatic gear changing system for

manual gearboxes. Opticruise is constructed in more or less
the same way as the Scania CAG system, the major difference
being that the driver only needs to use the clutch pedal when
starting, stopping and shunting.
The system is able to change gear automatically without the
clutch because the engine is regulated to synchronous speed
for the gear that is to be engaged. This means that the elec-
tronics adapt both engine speed and torque to exactly the lev-
els required by the gearbox. This makes all gear changing
gentle and precise, increasing the service life of the entire
powertrain.
Opticruise requires the engine to be equipped with EDC. It
would not be possible, using a mechanical injection pump, to
control the engine with the speed and precision required for
Opticruise to work smoothly. Opticruise also requires the
vehicle to be equipped with ABS/TC in order to select the
correct gear, even if the drive wheels lose grip on a slippery

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road surface.
Using Opticruise, the driver can choose to drive with manual
or automatic gear selection. In manual gear selection driving
mode, the driver selects the gear and when it is changed
(depending on road speed and/or engine speed). The control
unit decides whether it is possible to change gear without the
driver using the clutch. If this is the case, the gear is immedi-
ately changed when the driver moves the driving mode selec-
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tor sideways. Otherwise, the driver has to depress the clutch

pedal in order to change gear.
In automatic gear selection driving mode, the control unit cal-
culates which gear is appropriate and carries out this shift
when the calculation is complete. In this case, gear changing
always takes place without the driver having to use the clutch
pedal. If the EDC cruise control is engaged, gear change is
automatic without the cruise control being disengaged. This
Normal applies until speed is so low that it is a question of stopping or
shunting. The clutch must then be used.
Hill In addition to the driving mode selector and its various posi-
tions, the driver can choose between two different driving
programs. This is done using a program selector beside the
driving mode selector. These programs are called Normal and
Hill. The Hill program is for steep upward slopes with more
than 5 % gradient.
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4 © Scania CV AB 1995 05:05-02 en

 General

The control unit varies the point at which it changes gear,

depending on the position of the program selector. When driv-
ing with the program selector set to Hill, gear changing is
faster than when the Normal program is engaged. If neces-
sary, the exhaust brake may also be used in order to quickly
reduce the speed of the engine.
Like the older CAG system, Opticruise has a selectable start-
ing gear which is programmed in one of the control unit mem-
ories. The driver can easily select the starting gear for the
average gross train weight of the vehicle combination. The
control unit retains this setting, even when power is inter-
rupted. In addition to this, the driver can temporarily select a
starting gear other than the one programmed in the memory.
This is fully described in the driver’s manual.
The control unit has a built-in warning system. This has made
it possible to reduce the inconvenience in the event of a fault.
CLU MODE Opticruise has two built-in emergency driving programs. The
first of these, clutch mode, is activated in the case of less seri-

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ous faults and the driver has to depress the clutch pedal every
time a gear is changed. If the driving mode selector is set to
automatic, Opticruise still preselects the gear as normal. In
this situation, Opticruise works in the same way as Scania
LIMPHOME CAG.
In the case of more serious faults, the driver should activate a
limp home program. This makes it possible to drive the vehi-
cle to a workshop, even if something like a sensor is faulty.
This means that the vehicle can be run, even if the emergency
driving program feels basic with its manually-requested com-
pressed air gear changes.
The Opticruise system interacts with the braking effect of the
diesel engine, the exhaust brake and the Scania retarder, if the
vehicle is fitted with this. This reduces brake wear, reducing
running costs. In addition, wear to the entire powertrain is
reduced as power is transferred more gently than on vehicles
with manual gearboxes.
However, the greatest advantage, not least financially, is of
course improved driver comfort. Opticruise enables the driver
to maintain concentration longer than when driving a vehicle
with manual gear changing. This is an advantage for both run-
ning costs and road safety.

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General

Controls and operation

5 4

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1
2

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The above drawing shows the controls used for 1 Driving mode selector with positions R, N,
Opticruise. The clutch pedal, controls for EDC A and M. The driver is able to command up
cruise control and auxiliary brake control unit and downshift by moving the selector lever
also affect the system. to the side.
For example, the auxiliary brake may request 2 Program selector with Normal and Hill
that the engine brake program be activated in positions. The Hill position is for use on
order to increase engine speed and therefore steep slopes, preferably with the driving
coolant flow. This is essential for optimum mode selector set to M (manual).
retarder performance.
3 Switch for activating engine brake pro-
When driving with the cruise control, the sys-
gram and exhaust brake.
tem changes gear automatically provided the
driving mode selector is set the position A. The
4 Diagnostics switch
cruise control is deactivated using the clutch
pedal, brake pedal, retarder lever, cruise con-
5 Gear indicator with display and buzzer.
trol OFF button or using the exhaust brake
switch on the floor.

6 © Scania CV AB 1995 05:05-02 en

 Description of operation

Description of operation From automatic position A, the driver can at

any time move the lever to manual position M
and vice versa. This can be useful if you, for
Gear changing example, want to ”lock” a gear on a slippery
road surface. The same applies if he wants to
Driving in automatic position A means that the shift manually, for example on steep hills.
system changes gear automatically in accord-
ance with the driving program set using the Note: On uphill slopes greater than 8 %, it may
program selector, either ”Normal” or ”Hill”. be necessary to drive with the driving mode
selector set to M and with the program selector
However, the gear selected automatically can set to ”Hill”. This gives the fastest possible
be changed at any time by the driver by mov- gear changing, which means that the vehicle
ing the driving mode selector to the side. The does not lose so much speed during changing.
control unit always checks that the driver’s
selection is within reasonable limits. Opticruise controls the engine via EDC
The driver can even preselect a gear that Gear changing when driving is done by
appears completely inappropriate under the cir- Opticruise controlling the engine via EDC to
cumstances, such as 3rd when driving in 7th. synchronous speed for the gear that is about to
There are two conditions that must be met for be engaged, without the driver using the clutch

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this to work. pedal. This means that both engine speed and
torque are adjusted to precisely the level
• The vehicle must lose speed (be retarded).
required by the gearbox.
• The driving mode selector must be set to In order to make gear changing easier, engine
manual and the program selector to Hill. torque is reduced in a controlled manner just
The gearbox then starts the shift by first going before the gear is disengaged.
to neutral. The control unit then prepares itself Gear changing takes place after the speed of
for the correct splitter level, correct lateral the moving parts in the gearbox has been syn-
stroke and the correct range before road speed chronized.
is reduced sufficiently for the particular gear
change to be requested. Towards the end of gear changing, engine
torque increases in a gentle and controlled
At the same time, engine speed is automati- manner to the level requested by the driver
cally increased to high idling, about 2500 rpm. using the throttle pedal. This means that gear
When road speed has decreased sufficiently, changing is always gentle and precise, increas-
the gear is engaged smoothly and gently. When ing the service life of the entire powertrain.
gear changing is complete, control of the
engine is returned to the driver. This precise control is made possible by com-
munication between the Opticruise and EDC
When driving, the driver can at any time move control systems.
the driving mode selector to neutral (N) when,
for example, approaching a traffic light. If he
changes his mind and the vehicle is still mov-
ing, it is possible to move the driving mode
selector back to one of positions A or M. The
control unit then selects a suitable gear, based
on the speed of the vehicle and other informa-
tion from sensors etc. It is not necessary to use
the clutch unless speed is too low.

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Description of operation

Description of the gear changing process

1 Gear change requested automatically or by the driver.
2 Engine regulated so that there is no torque on the gearbox
input shaft.
3 Gearbox set to neutral.
4 Engine regulated to synchronize the speed of the gearbox
input shaft and the moving parts for the gear to be
engaged.
5 Gear engaged.
6 The engine is regulated to the required torque. The
Opticruise then returns control of the engine to the driver.
• During certain upshifts, the exhaust brake is used to more
quickly brake the engine to the correct speed in relation to
the gear selected.

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• When driving in automatic (A), the control unit continu-
ously calculates which gear is most suitable. When this cal-
culation shows that a gear other than the one engaged
would be more suitable, the gear change takes place imme-
diately. This may be either a single change or a block
change.
The calculation of appropriate gear is made based on the fol-
lowing data:
- Position of program selector
- Current road speed
- Current acceleration
- Current torque
- Total gear ratio
- Throttle pedal position
- Any request for the activation of the engine brake program
from the driver or from the auxiliary brake control unit.

8 © Scania CV AB 1995 05:05-02 en

 Description of operation

Engine brake program Programming start-off gear

The function of the engine brake program is to The system permits free choice of starting gear
give optimum engine braking in all driving between 1st and 4th. 1st or 2nd are normally
conditions. The engine brake program has used, but it may be appropriate to use another
nothing to do with the Normal/Hill program one in extreme cases.
selector, but is controlled by a separate switch
on the floor of the cab. Note: When the vehicle is heavily loaded, 1st
or 2nd must be used. Otherwise, the clutch
In order to use the engine brake program, the will be subjected to excessive wear.
throttle pedal must be fully released.
It may sometimes be necessary to start in a
A short press on the floor switch is all that is gear other than the one programmed. This can
required to activate the engine brake program. be done, irrespective of whether the driving
mode selector is set to A or M. Simply move
This means that upshift is delayed as the con- the driving mode selector to the side until the
trol unit maintains the gear for longer before required gear is shown on the display. The
changing up, increasing engine brake output. vehicle can now be started. The ordinary start-
ing gear remains programmed in the control
However, if the floor switch is held down all unit memory. More information can be found
the time, the exhaust brake is also engaged and

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in the driver’s manual.
downshift takes place earlier.
If the brake pedal is held down, the upshift Kick-down
points change. The control unit is informed of By pressing the throttle pedal from full throttle
this via the brake lamp switch. to kick-down, the gear changing points are
The engine brake program is connected until raised, usually causing faster downshift.
the throttle pedal is next depressed.
If the vehicle is equipped with an auxiliary
Auxiliary brake system
brake system with Scania retarder, the engine See ”Engine brake program”.
brake program can be automatically engaged
(if appropriate) when using the retarder. This is
done by the auxiliary brake control unit. The
intention is to raise engine speed and thus cool-
ant flow, providing the retarder with maximum
braking effect and activation time.

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Description of operation

EDC Cruise control

When driving with the cruise control, the system automati-
cally change gear if the driving mode selector is set to A. It is
however still possible to manually control gear selection in
both positions A and M, without disengaging the cruise con-
trol.
If the driving mode selector is set to N when the vehicle is
being driven with the cruise control activated, engine speed is
increased to high idling (i.e. the engine surges). The driver
should therefore disengage the cruise control before setting
the driving mode selector to N.
The cruise control is disengaged using the clutch pedal, brake
pedal, retarder lever, cruise control OFF button or the exhaust
brake switch on the cab floor.

ABS/TC

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The Opticruise control unit communicates with the ABS/TC
system. If there is wheel lock (causing ABS control) or spin
(causing TC control), the Opticruise is very reluctant to
change gear and does so according to special criteria. When
the driving mode selector is set to A, the Opticruise endeav-
ours to maintain the engaged gear.

Power take-offs
The control unit is configured for two types of power take-off,
PTO EK/ED and PTO EG.
PTO EK/ED provides torque compensation and therefore very
smooth gear changing if the vehicle is driven with an engine-
driven power take-off engaged (Max. compensation 200 Nm).
If the ED120 is used to drive a hydraulic pump, there may be
a lack of space around the longitudinal stroke cylinder. If this
is the case, turn the longitudinal stroke cylinder the other way
and move the compressed air couplings so that they swap
places.
PTO EG is for gearbox-driven power take-offs. If the vehicle
is driven with this input signal active, all gear changing is
blocked. The text PTO also flashes on the display if the vehi-
cle is driven above a certain speed.

10 © Scania CV AB 1995 05:05-02 en

 Description of operation

Miscellaneous Power supply and fuses

Generally, Opticruise continues to work if a
Control unit configuration fuse blows while the vehicle is being driven. It
The control unit contains all programming nec- may, however, be impossible to start the sys-
essary for a number of different Scania ver- tem the next time.
sions. So that the control unit fits each Scania, The control unit is protected by two fuses:
it must first be configured so that it uses the
correct program for the particular vehicle. This • Fuse 41 is used for 30 supply.
is equivalent to the code plug in other (less
modern) control units, such as for CAG. • Fuse 5 is used for 15 supply.
The required configuration is fed into the con- Power to the control unit is usually interrupted
trol unit at manufacture using a PC. Configura- using the starter switch. What happens then is
tion may be changed later by qualified that control unit 15 supply to pin 55 is broken.
personnel. When this happens, important data is trans-
ferred from the RAM to the EEPROM and
Configuration must contain the following stored there until the next start. The control
information: unit then goes into rest state, despite the fact
that 30 supply from the batteries is still applied

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• Vehicle category (e.g. truck) to pin 19.
• Chassis number • If fuse 41 for 30 supply blows, or if a bat-
• Part No. for control unit software tery cable is removed, data cannot be trans-
ferred from the RAM to the EEPROM and
• Gearbox type be stored. The control unit ”forgets” any
newly-programmed starting gear as well as
• Engine type and version new fault codes.
• Rear axle ratio • If fuse 5 for the 15 supply blows, data is
transferred as normal from RAM to EEP-
• Wheel rolling radius ROM and stored there. In this situation, the
control unit believes that the starter key has
• End-of-line data (date, signature)
been set to position 0. This means that it is
not possible to restart Opticruise until the
fault has been corrected.

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Description of operation

Interaction with other systems

The figure opposite shows which other systems • Opticruise is coupled to the auxiliary brake
are connected to Opticruise and in which system to make it possible to engage the
directions data is transferred. engine brake program to optimize the
retarder and achieve maximum braking
Any faults are transmitted in the same power in kW.
direction. This means that a fault in the
ABS/TC system can manifest itself in the When the auxiliary brake has requested the
Opticruise system, but not vice versa. exhaust brake to retard the vehicle, the
Opticruise will still be able to control the
Where appropriate, the figure applies to all exhaust brake for gear changing.
optional equipment affected.
• The Opticruise is coupled to the EDC sys- When the gear change is complete, the
tem to enable synchronous control of the exhaust brake will again be used to retard
speed of the gearbox input and output the vehicle. Prioritization of the various

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shafts. The particular gear change does not tasks of the exhaust brake is controlled by
take place until these speeds correspond the exhaust brake control unit (EEB).
with each other.
If the vehicle has an auxiliary brake, the
The communication between the Opticruise Opticruise forwards the speed signal from
and the EDC covers a wide range of data, the speed sensor on the gearbox output shaft
such as engine speed, requested and actual to the auxiliary brake control unit.
torque, throttle pedal position, coolant tem- • Opticruise is connected to the tachograph so
perature and cruise control. that it can use the speed information from
this to check that other speed signals are
Communication is via two CAN leads and is reasonable.
for such things as executing engine-control-
led gear changing and determining which
gear should be selected at any particular
time.
• The Opticruise is coupled to the ABS/TC
system to receive information on ABS con-
trol, TC control, wheel speeds etc.

The communication between Opticruise and

ABS/TC is used for confirming such things
as the suitability of the gear selection. If the
wheels are spinning or slipping, Opticruise
would be “fooled” into selecting the wrong
gear. The speed of each wheel is also used
to check that other speed signals appear
plausible.

Communication is via the two CAN leads.

12 © Scania CV AB 1995 05:05-02 en

 Description of operation

ABS/TC
Opticruise

Exhaust brake
Auxiliary brake

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system with
Scania retarder

EDC

Tachograph

Signal paths between the Opticruise control unit

and other computer-controlled systems that may be
in the vehicle.

Any faults are transferred from one system to

another in the same direction as communication
(see arrows).

05:05-02 en © Scania CV AB 1995 13

Description of operation

Opticruise, design 12 The diagnostic switch is used to activate

the test program built into the control unit
Item numbers refer to the drawing opposite. and for erasing fault codes.
1 The floor switch is used to activate the 13 Opticruise receives information from
engine brake program and exhaust brake. ABS/TC on speed, slip and possible wheel
In vehicles with no auxiliary brake, the spin in order to select the correct gear at
exhaust brake is used in combination with any moment. In addition, Opticruise must
the engine brake program when the floor be able to prevent gear change if the drive
switch is held down. The signal goes via wheels lose grip. This is for safety.
the auxiliary brake control unit if the vehi-
cle has this. Also see point 14. 14 Opticruise uses the exhaust brake to adapt
engine speed during certain gear changing
2 Two switches provide data on the position procedures, but the exhaust brake is nor-
of the clutch pedal (released, partly or fully mally used to brake the vehicle.
depressed).
The exhaust brake control unit prioritizes
3 EDC informs the control unit that the requests depending on driving conditions.
driver is braking. The engine brake pro- The exhaust brake can be activated auto-
gram then uses slightly shifted upshift matically, manually or by the auxiliary

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points. brake control unit.
4 The tachograph provides a speed signal 15 The engine speed sensor is used to be able
which Opticruise compares with the other to synchronize the speeds of the gearbox
speed signals. These come from ABS/TC input and output shafts when changing
and the gearbox output shaft. gear. The signal goes via the EDC and
5 The throttle pedal sensor provides data on through the communications circuit.
requested throttle and kick-down. The 16 The solenoid valves on the gearbox carry
potentiometer signal goes via the EDC out each gear change by releasing com-
control unit. pressed air to the longitudinal and lateral
6 The gear indicator with display and buzzer stroke cylinders. In turn, the cylinders acti-
is used to display driving program, which vate the gear selector shaft.
gear is engaged, fault messages etc. 17 The hall effect sensor and the confirmation
8 The driving mode selector informs the con- switches monitor and confirm gear chang-
trol unit about requested driving mode and ing movement.
if the driver wants to actuate the automatic
system by commanding a change up or
down.
9 The program selector has two positions.
The Normal position provides optimum
fuel economy and the box changes gear
calmly and comfortably. The Hill mode
provides a faster gear changing cycle at
higher engine speed.
10 Diagnostic socket for PC via interface
(Scania VCI).
11 PC with Scania Diagnos 2 fault tracing
program provides the fastest result when
fault tracing.

14 © Scania CV AB 1995 05:05-02 en

 Description of operation

The drawing below is general and applies to all optional equipment affected. Only relevant sec-
tions apply to vehicles with less equipment.

10 11

4
1 2 3 5 12
6
8
9

PTO EK/ED 21

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14
22
PTO EG
OPTI−
RETARDER 20 CRUISE 13 ABS/TC

EDC 19

15 16 17 18

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18 The speed sensor on the gearbox output 21 PTO EK/ED provides torque compensa-
shaft is used to calculate vehicle speed and tion during engine-controlled gear chang-
to confirm other speed signals from ing and therefore an excellent level of
ABS/TC and the tachograph. A corre- comfort if the vehicle is driven with an
sponding output signal is relayed to the engine-driven power take-off engaged.
auxiliary brake control unit.
22 PTO EG is for gearbox-driven power take-
19 Control of engine torque and speed is offs. When this input signal is active, all
requested by Opticruise but carried out by gear changing is blocked and the clutch
EDC. Just when Opticruise is controlling cannot be used.
the engine, the control unit continuously
checks that actual torque corresponds to
the requested level.
20 The auxiliary brake system control unit can
request Opticruise to activate the engine
brake program.

05:05-02 en © Scania CV AB 1995 15

Description of operation

Warning system
The control unit takes various action in the case of faults. This
is to prevent the fault having expensive consequences. For
example, the control unit has two different emergency gear
changing programs. The first of these still provides good driv-
ability while the second requires more from the driver. The
intention of this is that minor faults should not cause too much
inconvenience.

CLU MODE Certain types of less-serious fault cause the control unit to
switch from normal operation to the simpler of the two emer-
gency gear changing programs. The text ”CLU MODE”
C (clutch mode) is shown on the gear indicator display. In this
case, the driver is required to use the clutch for each gear
change. While the control unit is working in this mode, the
letter C will be displayed near the left of the display.
NORMAL
If the fault disappears on its own, the control unit immediately
returns to normal operation. The display then shows ”NOR-

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MAL”.
FAILURE
In the case of more serious faults, ”FAILURE” is displayed. If
this happens when driving, the control unit locks the engaged
gear. This gear alone is shown on the display. The driver must
then stop the vehicle and activate the ”LIMPHOME” emer-
gency gear changing program. This process is described in
detail in the Opticruise driver’s manual.

Fault code messages

When the driver switches off the power, the message ”CHK
CHK CODE CODE” is displayed if the control unit has stored any fault
codes during driving. This message is repeated when the
power is switched back on again.

ERROR1 ”ERROR1” or ”ERROR2” means that the control unit has

supplied faulty signals or no signals to the display. A PC must
ERROR2 be used to read any fault codes.
”CONFIG” means that the configuration of the control unit is
not correct. In this case, change the configuration of the con-
CONFIG trol unit using a PC and Scania Programmer.

16 © Scania CV AB 1995 05:05-02 en

 Description of operation

Reading fault codes

Fault codes are read in the first part of the Opticruise test pro-
gram. This test program is described in full on pages 59 - 69
of this booklet.
However, describing how to read fault codes would be a suita-
ble introduction to the list of fault codes in the next chapter
and the method is therefore also shown here.
1 Stop the vehicle and switch off the engine.
2 Switch on the power using the starter key. Wait for five
seconds and then hold the diagnostic switch depressed for
TESTING at least a half second. Release it. ”TESTING” is shown on
the display and the buzzer sounds.

Do not touch the diagnostic switch for the moment. The

test program has now started. All parts of the display light
for one second and the buzzer sounds.
ECU NO

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3 ”ECU NO” is displayed, directly followed by the part
number of the control unit hardware.
PROG NO
4 ”PROG NO” is displayed, directly followed by the part
number of the control unit software.
CHASSNO
5 ”CHASSNO” is displayed, directly followed by the vehi-
cle chassis number.
F CODES
6 ”F CODES” is displayed, directly followed by any fault
codes stored. More on this below.
• The fault codes are displayed one at a time, with two sec-
onds between them.
• When all stored fault codes have been displayed, the
buzzer sounds briefly. The stored fault codes are then dis-
played again. This may be repeated any number of times,
E010 003 so there is no danger if you should lose concentration.

The display can, for example, look like the figure to the
left. A shows the number of the fault code (10 in this case)
A B and B shows how many times this fault code has been reg-
istered (3).
7 Make a note of the fault codes. Run through the test pro-
gram. Press the diagnostic switch to switch between the
various stages of the test. See pages 59 - 69.

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Description of operation

Erasing fault codes

It may be necessary to reset the warning system
every now and then. Someone may, for exam-
ple, have unplugged a cable while the power
was switched on. This can easily happen and the
control unit will then believe that a genuine fault
has arisen.
The warning system is either reset using the
diagnostic switch, concealed behind the cover
on the instrument panel, or using a PC con-
nected to the vehicle’s diagnostic socket in the

05_5161
central electric unit.
Fault codes are extremely useful in the work-
shop as they facilitate fault diagnosis.
• In the driver’s manual, there is an explana-
tion of how to erase fault codes. However, it

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is also advised that they should not be erased
unnecessarily and that it is preferable, if pos-
sible, to seek advice at a workshop.
The symbols for the various switches are on the
inside of the lid. These can be seen when the lid
is opened. The Opticruise symbol is shown to
the right.

When the warning system is reset, all fault

codes are erased. Proceed as follows: ERASED!
1 Switch off the power using the starter key.
2 Press the diagnostic switch and hold it
down. Switch on the power.
3 The buzzer gives a short signal. When the
text ”ERASED” is displayed, erasure is
complete.

18 © Scania CV AB 1995 05:05-02 en

 Fault codes

Fault codes

General
The control unit acts fast and accurately, according to certain
instructions. It has no imagination and no judgement. When it dis-
covers a fault, or anything it interprets as abnormal, it reacts
immediately and generates fault codes. The warning system is
capable of generating around 70 different fault codes.

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Despite the advanced and ”farsighted” soft- Faults that do not generate fault
ware, a fault can arise which the control unit is codes
unable to distinguish from something which
might happen during normal operation. If this The following are the faults which do not cause
is the case, no fault code is generated. There is a fault code to be generated that we are aware
always a limit to how complete monitoring can of at the time of going to press.
be. This applies to all types of control unit.
• Fuse 5 blown (15 supply).
Limitations • Break in the diagnostics switch circuit.
It is not only ”genuine” faults that lead to the • Break in the floor switch circuit.
generation of fault codes. It is sufficient that
someone has unplugged a cable while the • Break or continuous signal from program
power was on. This can easily happen and the selector (Normal/Hill).
control unit will then believe that a fault has
arisen. • Break in circuit to the exhaust brake control
unit. Fault code 14 is generated in some, but
As for cases of loose contact, the fault may no not all, cases.
longer be present, but the fault code is stored in
the control unit memory until it is erased. It is • Break to gear indicator.
at least possible then to see which circuit the • Broken lamp in gear indicator.
fault was in and look for the cause there, even
if there is currently no fault.

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Fault codes

Explanations CAN: Stands for controller area network. CAN

communication is used to reduce the number of
Several new terms are used in the fault code cables in the vehicle. This is intended to
list or in the connection diagram in group 16. increase reliability.
These terms are explained below.
Vehicles with Opticruise have a communica-
tions circuit consisting of two cables, CAN
EEPROM: Stands for electrically erasable high (pin 38) and CAN low (pin 20).
programmable read only memory. Memory is In simple terms, CAN communication can be
retained, even if power is broken using the likened to radio technology. Data signals
starter key. The contents can be erased and through a CAN cable can be likened to radio
updated during service, using a PC and Scania waves through the air.
Programmer.
When listening to the radio, the receiver is set
This memory contains the control unit configu- so that one radio station is heard at one time.
ration, programmed starting gear, any fault This is the only station that can be heard,
codes etc. despite the fact that there are many radio sta-
tions broadcasting at the same time.

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A control unit does more or less the same thing
with the data coming through a CAN cable. It
listens for things such as information from
FLASH memory: This memory contains the EDC on coolant temperature, receives this
complete basic programming of the control value and uses it in calculations.
unit. The content remains, even if power is
switched off using the starter key. The basic The control unit receives all CAN signals that
program can be changed during service using a are sent through the communications circuit in
PC connected to the diagnostic socket. a special memory. This memory can be likened
to a number of radio receivers, set to different
radio stations in order to hear several, particu-
lar radio programmes at the same time. In this
way, the control unit always knows what is
RAM: Stands for random access memory. The happening.
content disappears every time the power is
switched off using the starter key or if power is This is nothing that a mechanic needs to worry
lost for any other reason. about. The only thing to remember is that it is
not possible to check CAN signals using a mul-
This memory stores and processes the various timeter. This is not even necessary as we have
control unit driving data from such things as precise fault codes.
sensors, controls and adjacent systems (EDC,
ABS and the retarder).

20 © Scania CV AB 1995 05:05-02 en

 Fault codes

Fault code 1 Fault: Fault in integrated control unit memory.

Cause: Test calculation of content of FLASH memory did not
provide the result the control unit was expecting.
Comment: FLASH memory itself contains basic control
unit program. The control unit checks that the FLASH mem-
ory is working as follows. All memory addresses are added
together to provide a sum. This sum is then used in a test cal-
culation which must provide the ”correct answer”. Otherwise,
this fault code is generated.
Action: Change control unit.

Fault: Fault in integrated control unit memory.

Fault code 2
Cause: Test calculation of content of EEPROM memory did

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not provide the result expected by the control unit.
Comment: EEPROM memory contains the configuration of
the control unit. Configuration controls which parts of the
basic program are used for the particular vehicle. When the
control unit checks that the EEPROM memory is working, the
following happens. All values that are important for configu-
ration are added up to a sum. This sum is then used in a test
calculation which must provide the ”correct answer”. Other-
wise, this fault code is generated.
Action: Correctly configure the control unit using a PC. If
this does not help, change the control unit.

Fault: Fault in integrated control unit memory.

Fault code 3
Cause: The control unit’s test of the RAM has shown that
some of the memory cells are not working properly.
Comment: The RAM is the actual working memory of the
control unit. It is here that all calculations are made.
When the control unit checks that the RAM is working prop-
erly, the following happens. Firstly, the control unit writes
certain values into the RAM and then reads these same values
to check that they have not become confused . If the control
unit interprets any deviation, this fault code is generated.
Action: Change control unit.

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Fault codes

Fault: Break or short in circuit for UX supply.

Fault code 4
Cause: Control unit has detected that power consumption
from pin 36 on the control unit (the so-called UX feed, +24V)
is either too low or too high.
Comment: The control unit gives UX supply on pin 36 to
supply the sensors, controls and display with power. The UX
supply enables the control unit to sense both open and short
circuits as they cause abnormal power consumption. It is this
abnormal power consumption from pin 36 which causes fault
code 4 to be generated.
Open circuit: The circuit consumes no current. Short circuit:
The circuit consumes high current.
In order for the fault code to be regenerated, power consump-
tion must suddenly change, due to something such as loose
contact. If the fault remains, the fault code is regenerated each
time the control unit attempts to activate the UX supply.

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High current in the UX circuit can be caused by such things as
shorted sensors.
Action: Check the UX circuit, wiring and components.

Fault: Fault in voltage supply in control unit.

Fault code 5
Cause: Control unit could not confirm its own internal U15
supply when the driver switched on the power using the
starter key.
Comment: The control unit started working when the power
was switched on, despite it not being possible to confirm U15
supply in the test circuit monitoring this.
When this fault arises, it is not possible for the EEPROM to
store new information. This means that the control unit ”for-
gets” any newly-programmed starting gear, and any newly-
generated fault codes. The number of faults is displayed as 1,
even if there are several. It is possible to drive the vehicle, but
it should be repaired as soon as possible as certain safety fea-
tures may be jeopardized.
Action: Change control unit.

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 Fault codes

Fault: Fault in monitoring feature inside control unit.

Fault code 7
Cause: The integrated watchdog relay does not activate when
the control unit starts working, or this relay is already acti-
vated when the driver switches on the starter power (this
should not be the case).
Comment: The control unit has detected a malfunction in one
of its internal safety features. Each malfunction of this type
causes the watchdog relay to alarm, generating fault code 7.
If the watchdog relay does not activate, power supply is lost to
all control unit outputs. Not even the starter gear can be
engaged, making the vehicle unusable.
Action: Change control unit.

Fault: Not possible to regulate engine speed to correct level

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Fault code 14 when changing gear.
Cause: The control unit has received a message from the
EDC via the communications circuit (pins 20 and 38) which
indicated an incorrect response from the engine. The exhaust
brake may have been activated during gear changing without
the Opticruise requesting this.
Comment: Requested torque exceeds permitted value for
engine-controlled gear changing when the gearbox has been
confirmed to be in neutral. This can happen if a gear is
engaged when the control unit is not expecting it. A possible
cause of this might be the slider in the gearbox breaking. If
this fault arises, the driver must use the clutch for every gear
change. CLU_MODE is displayed.
Action: Start by checking the sensor signals for gear position
and then the gearbox itself.

Fault: EDC gives a torque which does not correspond to the

Fault code 15 requested torque.
Cause: When the Opticruise control unit requested a particu-
lar torque via the communications circuit (pins 20 and 38),
EDC responded with a response which Opticruise considered
to indicate impossible values.
Continued >

05:05-02 en © Scania CV AB 1995 23

Fault codes

Comment: Requested torque from Opticruise is ”translated”

in this manner to actual control rack position in the injection
pump. The Opticruise control unit continuously checks that
each response of this type from EDC corresponds with the
expected result. If this fault arises, the driver has to use the
clutch whenever changing gear. CLU_MODE is displayed.
Action: Check whether the EDC control unit has generated
any fault codes. Check that the EDC control unit has the cor-
rect part number. Check connectors and wiring. End by
checking the position of the control rack in the injection
pump.

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Fault: NO signal or impossible signal from driving mode
Fault code 19 selector.
Cause: The control unit has received a signal on at least two
of pins 10, 11, 28, 29, 47 and 48 at the same time, or there is
no signal at all from the driving mode selector. These signals
are provided with UX voltage (+24V).
Comment: These signals are impossible as the driving mode
selector can only be in one position at a time.

If this fault arises, the control unit does not ”obey” the driving
mode selector. Either there is no signal at all, or the control
unit has received conflicting signals in one of the following
combinations:

Upshift and downshift at the same time (pins 10 and 28).

Reverse and automatic position at the same time (pins 48
and 29).
Reverse and manual position at the same time (pins 48
and 47).
Neutral and manual position at the same time (pins 11
and 47).
Continued >

24 © Scania CV AB 1995 05:05-02 en

 Fault codes

Action: Check the driving mode selector, connectors and wir-

ing. Use wiring diagrams and a multimeter to check the driv-
ing mode selector.

Fault: Impossible signals from clutch switches.

Fault code 22
Cause: Control unit has sensed that pin 8 received a signal
when there was no signal on pin 45.
Comment: The lower clutch pedal switch has been closed
despite the upper clutch pedal switch not being closed. It
should not be possible for something like this to happen when
driving.
When these switches are activated, they are closed to system

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earth (0V).
The gearbox cannot change gear automatically if this fault has
arisen. The vehicle can, however, be operated using the LIM-
PHOME emergency gear changing program.
Action: Check both clutch pedal switches, connectors and
wiring.

Fault: Uninterrupted signal from the lower clutch pedal

Fault code 23 switch.
Cause: Control unit has sensed that there was a signal for too
long on pin 8.
Comment: The clutch pedal switch cannot be closed for this
long when driving normally.
When this switch is activated, it is closed to system earth
(0V).
The gearbox cannot change gear automatically if this fault has
arisen. The vehicle can, however, be operated using the LIM-
PHOME emergency gear changing program.
Action: Check the lower clutch pedal switch, connectors and
wiring.

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Fault codes

Fault: Uninterrupted signal from upper clutch pedal switch.

Fault code 24
Cause: Control unit has sensed that the signal remained for
too long on pin 45.
Comment: The clutch pedal switch cannot be closed for this
long when driving normally, unless the driver rests his foot on
the clutch pedal when driving.
When this switch is activated, it is closed to system earth
(0V).
The gearbox cannot carry out engine-controlled gear changing
in manual position if this fault arises.
Action: Check the upper clutch pedal switch, connectors and
wiring.

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Fault: Uninterrupted signal from floor switch for engine
Fault code 26 brake program.
Cause: Control unit has sensed that the signal remained for
too long on pin 27.
Comment: The floor switch cannot be closed for this long
during normal driving.
When this switch is activated, it is closed to +24V. Note that
the signal to pin 27 does not always come from the floor
switch. The retarder control unit can also send the same sig-
nal.
If this fault arises, the control unit is forced to use the engine
brake program.
Action: Check the floor switch, connectors and wiring. Check
if there are any fault codes stored in the retarder control unit
(if the vehicle has a retarder).

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 Fault codes

Fault: Uninterrupted signal from diagnostic switch.

Fault code 27
Cause: Control unit has sensed that the signal remained for
too long on pin 30.
Comment: It is not possible for the diagnostic switch to be
depressed this long during normal use.
When this switch is activated, it is closed to system earth
(0V).
If this fault arises when the driver switches on the power, all
fault codes that can be shown on the display will be erased. It
may also be impossible to start the test program.
Action: Check the diagnostic switch, connectors and wiring.

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Fault: Impossible deviation, vehicle speed compared to tach-
Fault code 28 ograph.
Cause: The control unit has sensed that the difference in fre-
quency between the signals to pins 31 and 49 (which together
generate a frequency in the control unit) and the signal to pin
32 is too great.
Comment: The difference between the signal from the induc-
tive speed sensor on the gearbox output shaft and the tacho-
graph signal from the combined instrument was greater than
permitted.
Action: Check the road speed sensor on the gearbox output
shaft, the tachograph signal, connectors and wiring.

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Fault codes

Fault: Defective contact or loss of signal, vehicle speed sen-

Fault code 31 sor.
Cause: Control unit has sensed that the signals on pin 31
and/or pin 49 are too uneven.
Comment: Speed signal from the inductive road speed sensor
on the gearbox output shaft has varied more than permitted.
Speed must exceed a certain limit for the control unit to regis-
ter this fault.
Action: Check the road speed sensor on the gearbox output
shaft, connectors and wiring.

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Fault: Break or short circuit, vehicle speed sensor.
Fault code 34
Cause: Power consumption too low or too high on pin 31
and/or 49.
Comment: This fault can either be due to a break in the wir-
ing or in the actual sensor, or to a cable being shorted to chas-
sis earth or +24V. In this case, the control unit cannot feel that
the sensor in question is connected.
Action: Check the road speed sensor on the gearbox output
shaft, connectors and wiring.

Fault: Gear changing movement forward on the left-hand

Fault code 36 side commanded but not confirmed.
Cause: No confirmation for forward longitudinal stroke (pin
43) on the left-hand side (pin 42), despite several attempts to
activate the solenoid valves which release the compressed air.
Comment: The control unit counts both its own attempts and
those of the driver to change gear.
Continued >

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 Fault codes

Action: Start by checking the air hoses to the solenoid valves

and that the correct air pressure is reaching the solenoid
valves. Then check that the confirmation signals from the hall
effect sensors are transmitted correctly. Check the solenoid
valves for forward longitudinal stroke and left-hand lateral
stroke, connectors and wiring.

Fault: Gear changing movement backward on left-hand side

Fault code 37 ordered but not confirmed.
Cause: No confirmation for rearward longitudinal stroke (pin
6) on left-hand side (pin 42), despite several attempts to acti-
vate the solenoid valves which release the compressed air.
Comment: The control unit counts both its own attempts and
those of the driver to change gear.

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Action: Start by checking the air hoses to the solenoid valves
and that the correct air pressure is reaching these solenoid
valves. Then check that the confirmation signals from the hall
effect sensor are transmitted correctly. Check the solenoid
valves for rearward longitudinal stroke and left-hand lateral
stroke, connectors and wiring.

Fault: Gear changing movement forward in centre position

Fault code 38 commanded but not confirmed.
Cause: No confirmation for forward longitudinal stroke (pin
43), despite several attempts to activate the solenoid valve
which releases the compressed air.
Comment: The control unit counts both its own attempts and
those of the driver to change gear.
Action: Start by checking the air hoses to the solenoid valves
and that the correct air pressure is getting to the solenoid
valves. Then check that the confirmation signals from the hall
effect sensor are transmitted correctly. Check the solenoid
valve for forward longitudinal stroke, connectors and wiring.

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Fault codes

Fault code 39 Fault: Gear changing movement rearward in centre position

commanded but not confirmed.
Cause: No confirmation for rearward longitudinal stroke
(pin 6), despite several attempts to activate the solenoid valve
which releases the compressed air.
Comment: The control unit counts both its own attempts and
those of the driver to change gear.
Action: Start by checking the air hoses to the solenoid valves
and that the correct air pressure is getting to the solenoid
valves. Then check that the confirmation signals from the hall
effect sensor are transmitted correctly. Check the solenoid
valve for rearward longitudinal stroke, connectors and wiring.

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Fault: Forward gear changing movement on right-hand side
Fault code 40 ordered but not confirmed.
Cause: No confirmation for forward longitudinal stroke (pin
43) on right-hand side (pin 24), despite several attempts to
activate the solenoid valves which release the compressed air.
Comment: The control unit counts both its own attempts and
those of the driver to change gear.
Action: Start by checking the air hoses to the solenoid valves
and that the correct air pressure is getting to the solenoid
valves. Then check that the confirmation signals from the hall
effect sensor are transmitted correctly. Check the solenoid
valves for forward longitudinal stroke and right-hand lateral
stroke, connectors and wiring.

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 Fault codes

Fault: Gear changing movement rearward on the right-hand

Fault code 41 side commanded but not confirmed.
Cause: No confirmation for rearward longitudinal stroke (pin
6) on right-hand side (pin 24), despite several attempts to acti-
vate the solenoid valves which release the compressed air.
Comment: The control unit counts both its own attempts and
those of the driver to change gear.
Action: Start by checking the air hoses to the solenoid valves
and that the correct air pressure is getting to the solenoid
valves. Then check that the confirmation signals from the hall
effect sensor are transmitted correctly. Check the solenoid
valves for rearward longitudinal stroke and right-hand lateral
stroke, connectors and wiring.

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Fault: Gear changing movement to the left commanded but
Fault code 42 not confirmed.
Cause: No confirmation for left-hand lateral stroke (pin 42),
despite several attempts to activate the solenoid valve which
releases the compressed air.
Comment: The control unit counts both its own attempts and
those of the driver to change gear.
Action: Start by checking the air hoses to the solenoid valves
and that the correct air pressure is getting to the solenoid
valves. Then check that the confirmation signals from the hall
effect sensor are transmitted correctly. Check the solenoid
valve for left-hand lateral stroke, connectors and wiring.

05:05-02 en © Scania CV AB 1995 31

Fault codes

Fault: Gear changing movement to the right commanded but

Fault code 43 not confirmed.
Cause: No confirmation for right-hand lateral stroke (pin 24),
despite several attempts to activate the solenoid valve which
releases the compressed air.
Comment: The control unit counts both its own attempts and
those of the driver to change gear.
Action: Start by checking the air hoses to the solenoid valves
and that the correct air pressure is getting to the solenoid
valves. Then check that the confirmation signals from the hall
effect sensor are transmitted correctly. Check the solenoid
valve for right-hand lateral stroke, connectors and wiring.

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Fault: Gear changing movement laterally towards the centre
Fault code 44 position requested but not confirmed.
Cause: The control unit has sensed that a confirmation signal
for lateral stroke to the left (pin 42) or a lateral stroke to the
right (pin 24) is still present.
Comment: When the confirmation signal for the lateral neu-
tral position exceeds 10 V and no solenoid valve is activated,
a time count is initiated which then stops when the confirma-
tion signals for lateral stroke are no longer present. This fault
code is generated if the time count is not completed within a
predetermined time.
Action: Start by checking the air lines to the solenoid valves
and check that the correct air pressure is reaching the solenoid
valves. Then check that the confirmation signals from the
Hall-effect sensor are correctly received. Check the venting of
the solenoid valves for left and right-hand lateral stroke, the
return springs, connectors and wiring.

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 Fault codes

Fault: Loss of confirmation, forward stroke.

Fault code 45
Cause: Control unit has sensed the sudden loss of confirma-
tion signal on pin 43.
Comment: For the control unit to be able to check if the sig-
nal is lost, a complete gear change must first be completed.
Five seconds after the control unit has received confirmation
of the completed gear change, it starts to sense whether the
confirmation signal continues to be transmitted as it should
be. The control unit checks this until it commands the gearbox
to carry out the next gear change. This fault code is generated
if, for example, the gear is ejected mechanically.
Action: Check the hall effect sensor, connectors and wiring.

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Fault: Loss of confirmation, rearward stroke.
Fault code 46
Cause: Control unit has sensed the sudden loss of confirma-
tion signal on pin 6.
Comment: For the control unit to be able to check if the sig-
nal is lost, a complete gear change must first be completed.
Five seconds after the control unit has received confirmation
of the completed gear change, it starts to sense whether the
confirmation signal continues to be transmitted as it should
be. The control unit checks this until it commands the gearbox
to carry out the next gear change. This fault code is generated
if, for example, the gear is ejected mechanically.
Action: Check the hall effect sensor, connectors and wiring.

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Fault codes

Fault code 47 Fault: Loss of confirmation, right-hand lateral stroke.

Cause: Control unit has sensed the sudden loss of confirma-
tion signal on pin 24.
Comment: For the control unit to be able to check if the sig-
nal is lost, a complete gear change must first be completed.
Five seconds after the control unit has received confirmation
of the completed gear change, it starts to sense whether the
confirmation signal continues to be transmitted as it should
be. The control unit checks this until it commands the gearbox
to carry out the next gear change. This fault code is generated
if, for example, the gear is ejected mechanically.
Action: Check the hall effect sensor, connectors and wiring.

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Fault: Loss of confirmation, left-hand lateral stroke.
Fault code 48
Cause: Control unit has sensed the sudden loss of confirma-
tion signal on pin 42.
Comment: For the control unit to be able to check if the sig-
nal is lost, a complete gear change must first be completed.
Five seconds after the control unit has received confirmation
of the completed gear change, it starts to sense whether the
confirmation signal continues to be transmitted as it should
be. The control unit checks this until it commands the gearbox
to carry out the next gear change. This fault code is generated
if, for example, the gear is ejected mechanically.
Action: Check the hall effect sensor, connectors and wiring.

Fault: Loss of confirmation, neutral position.

Fault code 49
Cause: Control unit has sensed the sudden loss of confirma-
tion signal on pin 7.
Continued >

34 © Scania CV AB 1995 05:05-02 en

 Fault codes

Comment: For the control unit to be able to check if the sig-

nal is lost, a complete gear change must first be completed.
Five seconds after the control unit has received confirmation
of the completed gear change, it starts to sense whether the
confirmation signal continues to be transmitted as it should
be. The control unit checks this until it commands the gearbox
to carry out the next gear change. This fault code is generated
if, for example, the gear is ejected mechanically.
Action: Check the hall effect sensor, connectors and wiring.

Fault: No confirmation, neutral position.

Fault code 50
Cause: Control unit has not received confirmation signal on
pin 7 to confirm that the commanded gear change has been

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carried out.
Comment: When the solenoid valve for neutral is activated,
time measurement starts which is interrupted when the confir-
mation signal for neutral position exceeds 10 V. This fault
code is generated if time measurement is not carried out
within a preset time.
This fault code can only be generated when vehicle speed is
greater than 5 km/h or when the clutch pedal is fully
depressed.
Action: Check control cylinders, solenoid valve for neutral
position, compressed air lines, hall effect sensors, connectors
and wiring.

Fault: Continuous confirmation signal, neutral position.

Fault code 51
Cause: Control unit has sensed that the confirmation signal
remained for too long on pin 7.
Comment: Confirmation signal may not remain too long after
the command for forward longitudinal stroke or rearward lat-
eral stroke has been given. This fault code can be generated if
the gearbox is binding, for example in severe cold.
Action: Check control cylinders, solenoid valves, compressed
air lines, hall effect sensors, connectors and wiring.

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Fault codes

Fault: Impossible confirmation (impossible gear positions).

Fault code 52
Cause: Simultaneous confirmation from several gears at the
same time.
Comment: The signals are impossible because the Hall-effect
sensor and the confirmation switches should only be able to
confirm one gear changing movement at a time.
Any of the following confirmations have come at the same
time:
Neutral and forward confirmation (pin 7 and pin 43)
Neutral and rear confirmation (pin 7 and pin 6)
Forward and rear confirmation (pin 43 and pin 6)
Right and left confirmation (pin 24 and pin 42)
Low range and high range confirmation (pin 41 and pin 5)

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Low split and high split confirmation (pin 4 and pin 23).
Action: Check hall effect sensors, confirmation switches,
connectors and wiring.

Fault: Gear changing movement to low range commanded

Fault code 53 but not confirmed.
Cause: No signal on pin 41.
Comment: No confirmation for low range, despite several
attempts to activate the solenoid valve which releases com-
pressed air. Each gear changing attempt must take a certain
time in order to be counted.
Action: Check control cylinders, confirmation switches, the
low range solenoid valve, compressed air lines, connectors
and wiring.

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 Fault codes

Fault: Gear changing movement towards high range com-

Fault code 54 manded but not confirmed.
Cause: No signal on pin 5.
Comment: No confirmation for high range, despite several
attempts to activate the solenoid valve which releases com-
pressed air. Each gear changing attempt must take a certain
time in order to be counted.
Action: Check control cylinders, confirmation switches, the
high range solenoid valve, compressed air lines, connectors
and wiring.

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Fault: Gear changing movement towards low split com-
Fault code 55 manded but not confirmed.
Cause: No signal on pin 4.
Comment: No confirmation for low split, despite several
attempts to activate the solenoid valve which releases com-
pressed air. Each gear changing attempt must take a certain
time in order to be counted.
Action: Check control cylinders, confirmation switches, the
low split solenoid valve, compressed air lines, connectors and
wiring.

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Fault codes

Fault: Gear changing movement to high split commanded but

Fault code 56 not confirmed.
Cause: No signal on pin 23.
Comment: No confirmation for high split despite several
attempts to activate the solenoid valve which releases the
compressed air. Each gear changing attempt must take a cer-
tain time in order to be counted.
Action: Check control cylinders, confirmation switches, the
high split solenoid valve, compressed air lines, connectors and
wiring.

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Fault: Loss of confirmation, low range.
Fault code 57
Cause: The control unit has sensed the sudden loss of confir-
mation signal on pin 41.
Comment: For the control unit to be able to check if the sig-
nal is lost, a complete gear change must first be completed.
Five seconds after the control unit has received confirmation
of the completed gear change, it starts to sense whether the
confirmation signal continues to be transmitted as it should
be. The control unit checks this until it commands the gearbox
to carry out the next gear change. This fault code is generated
if, for example, the gear is ejected mechanically.
Action: Check confirmation switches, connectors and wiring.

38 © Scania CV AB 1995 05:05-02 en

 Fault codes

Fault: Loss of confirmation, high range.

Fault code 58
Cause: The control unit has sensed the sudden loss of confir-
mation signal on pin 5.
Comment: For the control unit to be able to check if the sig-
nal is lost, a complete gear change must first be completed.
Five seconds after the control unit has received confirmation
of the completed gear change, it starts to sense whether the
confirmation signal continues to be transmitted as it should
be. The control unit checks this until it commands the gearbox
to carry out the next gear change. This fault code is generated
if, for example, the gear is ejected mechanically.
Action: Check confirmation switches, connectors and wiring.

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Fault: Loss of confirmation, low split.
Fault code 59
Cause: The control unit has sensed the sudden loss of confir-
mation signal on pin 4.
Comment: For the control unit to be able to check if the sig-
nal is lost, a complete gear change must first be completed.
Five seconds after the control unit has received confirmation
of the completed gear change, it starts to sense whether the
confirmation signal continues to be transmitted as it should
be. The control unit checks this until it commands the gearbox
to carry out the next gear change. This fault code is generated
if, for example, the gear is ejected mechanically.
Action: Check confirmation switches, connectors and wiring.

05:05-02 en © Scania CV AB 1995 39

Fault codes

Fault: Loss of confirmation, high split.

Fault code 60
Cause: The control unit has sensed the sudden loss of confir-
mation signal on pin 23.
Comment: For the control unit to be able to check if the sig-
nal is lost, a complete gear change must first be completed.
Five seconds after the control unit has received confirmation
of the completed gear change, it starts to sense whether the
confirmation signal continues to be transmitted as it should
be. The control unit checks this until it commands the gearbox
to carry out the next gear change. This fault code is generated
if, for example, the gear is ejected mechanically.
Action: Check confirmation switches, connectors and wiring.

cardiagn.com
Fault: Solenoid valve for forward longitudinal stroke is live
Fault code 61 when it should not be.
Cause: Control unit output to solenoid valve for forward lon-
gitudinal stroke has been powered without the control unit
commanding this.
Comment: This fault code is generated if the control unit out-
put for the solenoid valve in question has been powered for
the wrong reason, for example due to a short circuit to +24
volts (e.g. in wiring). Otherwise, there is a fault in the control
unit itself.
Action: Disconnect the cable from pin 3 and measure using a
multimeter. Then check connectors and wiring.

40 © Scania CV AB 1995 05:05-02 en

 Fault codes

Fault: Solenoid valve for rearward longitudinal stroke is

Fault code 62 powered when it should not be.
Cause: Control unit output to solenoid valve for rearward lon-
gitudinal stroke has been powered despite the fact that control
unit has not commanded this.
Comment: This fault code is generated if the control unit out-
put for the solenoid valve in question has been powered for
the wrong reason, for example due to a short circuit to +24
volts (e.g. in wiring). Otherwise, there is a fault in the control
unit itself.
Action: Disconnect the cable from pin 22 and measure using
a multimeter. Then check connectors and wiring.

cardiagn.com
Fault: Solenoid valve for neutral position is powered when it
Fault code 63 should not be.
Cause: Control unit output to the solenoid valve for neutral
position has been powered despite the control unit not com-
manding this.
Comment: This fault code is generated if the control unit out-
put for the solenoid valve in question has been powered for
the wrong reason, for example due to a short circuit to +24
volts (e.g. in wiring). Otherwise, there is a fault in the control
unit itself.
Action: Disconnect the cable from pin 40 and measure using
a multimeter. Then check connectors and wiring.

05:05-02 en © Scania CV AB 1995 41

Fault codes

Fault: Solenoid valve for low range is powered when it

Fault code 64 should not be.
Cause: Control unit output to solenoid valve for low range
has been powered despite the control unit not commanding
this.
Comment: This fault code is generated if the control unit out-
put for the solenoid valve in question has been powered for
the wrong reason, for example due to a short circuit to +24
volts (e.g. in wiring). Otherwise, there is a fault in the control
unit itself.
Action: Disconnect the cable from pin 39 and measure using
a multimeter. Then check connectors and wiring.

cardiagn.com
Fault: Break or short in circuit to solenoid valve for forward
Fault code 65 longitudinal stroke.
Cause: Power consumption too low or too high from pin 3 on
the control unit.
Comment: When the solenoid valve for forward longitudinal
stroke is activated, the control unit can sense the following
cases. Break:Circuit not consuming any current. Short cir-
cuit:Current in circuit too high.
For the fault code to be regenerated, power consumption must
suddenly change, for example due to a defective contact. If
the fault remains, the fault code is regenerated each time the
control unit attempts to activate the solenoid valve in ques-
tion.
High current can be caused by such things as shorted wind-
ings in the solenoid valve coil.
Action: Check the solenoid valve for forward longitudinal
stroke, connectors and wiring.

42 © Scania CV AB 1995 05:05-02 en

 Fault codes

Fault: Break or short in circuit to solenoid valve for rearward

Fault code 66 longitudinal stroke.
Cause: Power consumption too low or too high from pin 22
on the control unit.
Comment: When the solenoid valve for rearward longitudi-
nal stroke is activated, the control unit can sense the following
cases. Break: Circuit not consuming any current. Short circuit:
Current in circuit too high.
For the fault code to be regenerated, power consumption must
suddenly change, for example due to a defective contact. If
the fault remains, the fault code is regenerated each time the
control unit attempts to activate the solenoid valve in ques-
tion.
High current can be caused by such things as shorted wind-
ings in the solenoid valve coil.

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Action: Check the solenoid valve for rearward longitudinal
stroke, connectors and wiring.

Fault: Break or short in circuit to solenoid valve for right-

Fault code 67 hand lateral stroke.
Cause: Power consumption too low or too high from pin 17
on the control unit.
Comment: When the solenoid valve for right-hand lateral
stroke is activated, the control unit can sense the following
cases. Break: Circuit not consuming any current. Short circuit:
Current in circuit too high.
For the fault code to be regenerated, power consumption must
suddenly change, for example due to a defective contact. If
the fault remains, the fault code is regenerated each time the
control unit attempts to activate the solenoid valve in ques-
tion.
High current can be caused by such things as shorted wind-
ings in the solenoid valve coil.
Action: Check the solenoid valve for right-hand lateral
stroke, connectors and wiring.

05:05-02 en © Scania CV AB 1995 43

Fault codes

Fault: Break or short in circuit to solenoid valve for left-hand

Fault code 68 lateral stroke.
Cause: Power consumption too low or too high from pin 53
on the control unit.
Comment: When the solenoid valve for left-hand lateral
stroke is activated, the control unit can sense the following
cases. Break:Circuit not consuming any current. Short circuit:
Current in circuit too high.
For the fault code to be regenerated, power consumption must
suddenly change, for example due to a defective contact. If
the fault remains, the fault code is regenerated each time the
control unit attempts to activate the solenoid valve in ques-
tion.
High current can be caused by such things as shorted wind-
ings in the solenoid valve coil.

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Action: Check the solenoid valve for left-hand lateral stroke,
connectors and wiring.

Fault: Break or short in circuit to solenoid valve for neutral

Fault code 69 position.
Cause: Power consumption too low or too high from pin 40
on the control unit.
Comment: When the solenoid valve for neutral position is
activated, the control unit can sense the following cases.
Break:Circuit not consuming any current. Short circuit: Cur-
rent in circuit too high.
For the fault code to be regenerated, power consumption must
suddenly change, for example due to a defective contact. If
the fault remains, the fault code is regenerated each time the
control unit attempts to activate the solenoid valve in ques-
tion.
High current can be caused by such things as shorted wind-
ings in the solenoid valve coil.
Action: Check the solenoid valve for neutral position, con-
nectors and wiring.

44 © Scania CV AB 1995 05:05-02 en

 Fault codes

Fault: Break or short in circuit to solenoid valve for low

Fault code 70 range.
Cause: Power consumption too low or too high from pin 39
on the control unit.
Comment: When the solenoid valve for low range is acti-
vated, the control unit can sense the following cases.
Break:Circuit not consuming any current. Short circuit: Cur-
rent in circuit too high.
For the fault code to be regenerated, power consumption must
suddenly change, for example due to a defective contact. If
the fault remains, the fault code is regenerated each time the
control unit attempts to activate the solenoid valve in ques-
tion.
High current can be caused by such things as shorted wind-
ings in the solenoid valve coil.

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Action: Check the solenoid valve for low range, connectors
and wiring.

Fault: Break or short in circuit to solenoid valve for high

Fault code 71 range.
Cause:Power consumption too low or too high from pin 54
on the control unit.
Comment: When the solenoid valve for high range is acti-
vated, the control unit can sense the following cases. Break:
Circuit not consuming any current. Short circuit: Current in
circuit too high.
For the fault code to be regenerated, power consumption must
suddenly change, for example due to a defective contact. If
the fault remains, the fault code is regenerated each time the
control unit attempts to activate the solenoid valve in ques-
tion.
High current can be caused by such things as shorted wind-
ings in the solenoid valve coil.
Action: Check the solenoid valve for high range, connectors
and wiring.

05:05-02 en © Scania CV AB 1995 45

Fault codes

Fault: Break or short in circuit to solenoid valve for low split.

Fault code 72
Cause: Power consumption too low or too high from pin 2 on
the control unit.
Comment: When the solenoid valve for low split is activated,
the control unit can sense the following cases. Break:Circuit
not consuming any current. Short circuit:Current in circuit too
high.
For the fault code to be regenerated, power consumption must
suddenly change, for example due to a defective contact. If
the fault remains, the fault code is regenerated each time the
control unit attempts to activate the solenoid valve in ques-
tion.
High current can be caused by such things as shorted wind-
ings in the solenoid valve coil.
Action: Check the solenoid valve for low split, connectors

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and wiring.

Fault: Break or short in circuit to solenoid valve for high

Fault code 73 split.
Cause: Power consumption too low or too high from pin 18
on the control unit.
Comment: When the solenoid valve for high split is acti-
vated, the control unit can sense the following cases.
Break:Circuit not consuming any current. Short circuit:Cur-
rent in circuit too high.
For the fault code to be regenerated, power consumption must
suddenly change, for example due to a defective contact. If
the fault remains, the fault code is regenerated each time the
control unit attempts to activate the solenoid valve in ques-
tion.
High current can be caused by such things as shorted wind-
ings in the solenoid valve coil.
Action: Check the solenoid valve for high split, connectors
and wiring.

46 © Scania CV AB 1995 05:05-02 en

 Fault codes

Fault: Fault in power supply to control unit.

Fault code 75
Cause: Control unit has sensed that there was no U30 power
supply when the driver switched off the power with the starter
switch.
Comment: The control unit has been switched off several
times in a row without being able to store its data from the
EEPROM. This may be because the control unit has been
switched off with no U30 supply connected to the control
unit. It may also be due to the control unit having been
exposed to strong disturbance which has caused the integrated
protective features in the control unit to act and restart it
repeatedly.
Action: Check the fuse for U30 supply to the Opticruise con-
trol unit, connectors and wiring.

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Fault code 76 Fault: The EDC cannot provide a reliable value for throttle
pedal position.
Cause: The control unit has received a message from EDC
via the communications circuit (pins 20 and 38) which shows
that the value from the throttle pedal sensor potentiometer is
impossible.
Comment: In this case, the communications circuit itself is
probably not faulty. Otherwise, the control unit would have
generated a different fault code (fault code 82 or 83).
Action: Check whether there are any fault codes stored in the
EDC control unit.

Fault: The EDC cannot provide a reliable value for current

Fault code 77 engine speed.
Cause: The control unit has received a message from EDC
via the communications circuit (pins 20 and 38) which shows
that the value from the engine speed sensor is impossible.
Comment: In this case, the communications circuit itself is
probably not faulty. Otherwise, the control unit would have
generated a different fault code (fault code 82 or 83).
Action: Check whether there are any fault codes stored in the
EDC control unit.

05:05-02 en © Scania CV AB 1995 47

Fault codes

Fault: The EDC cannot provide a reliable value for current

Fault code 78 vehicle speed.
Cause: The control unit has received a message from EDC
via the communications circuit (pins 20 and 38) which shows
that the value of the speed signal is impossible.
Comment: In this case, the communications circuit itself is
probably not faulty. Otherwise, the control unit would have
generated a different fault code (fault code 82 or 83).
Action: Check whether there are any fault codes stored in the
EDC control unit.

Fault: The EDC cannot provide a reliable value for brake

Fault code 79 pedal position.

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Cause: The control unit has received a message from EDC
via the communications circuit (pins 20 and 38) which shows
that the value from the brake pedal sensor is impossible.
Comment: In this case, the communications circuit itself is
probably not faulty. Otherwise, the control unit would have
generated a different fault code (fault code 82 or 83).
Action: Check whether there are any fault codes stored in the
EDC control unit.

Fault: The EDC cannot provide a reliable value for coolant

Fault code 80 temperature.
Cause: The control unit has received a message from EDC
via the communications circuit (pins 20 and 38) which shows
that the value from the temperature sensor is impossible.
Comment: In this case, the communications circuit itself is
probably not faulty. Otherwise, the control unit would have
generated a different fault code (fault code 82 or 83).
Action: Check whether there are any fault codes stored in the
EDC control unit.

48 © Scania CV AB 1995 05:05-02 en

 Fault codes

Fault: Fault in integrated control unit memory.

Fault code 81
Cause: The control unit test of communications circuit mem-
ory has shown that some of the memory cells are not working
properly.
Comment: The memory for the communications circuit is
used as a buffer to store information from adjacent systems
(such as EDC and ABS) and then to sort this information
before it is used by Opticruise. The control unit starts by feed-
ing specific values into the communications memory and then
reads these same values to check that they have not become
confused. If the control unit detects any deviation, this fault
code is generated.
Action: Change control unit.

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Fault: Fault in communications circuit.
Fault code 82
Cause: The control unit has sensed that the signal level in the
communications circuit has been faulty. This indicates an
open or short circuit somewhere beyond pins 20 and 38.
Comment: When the signal level fault has ceased, communi-
cation starts to work again with no further action.
Action: Check connectors and wiring. If these are not at fault,
then the control unit is faulty, but there is not much chance of
this.

Fault: No communications signal from EDC control unit.

Fault code 83
Cause: There has been an abnormally long delay in the
expected signal from EDC via the communications circuit
(pins 20 and 38).
Comment: The Opticruise control unit continuously receives
information from the EDC control unit and ”realizes” that
communication is working properly. If this information is not
present, fault code 83 is generated.
Action: Check to see whether there are any fault codes stored
in the EDC control unit. Check connectors and wiring in the
communications circuit.

05:05-02 en © Scania CV AB 1995 49

Fault codes

Fault: No communications signal from ABS control unit.

Fault code 84
Cause: There has been an abnormally long delay in the
expected signal from ABS via the communications circuit
(pins 20 and 38).
Comment: The Opticruise control unit continuously receives
information from the ABS control unit and ”realizes” that
communication is working properly. If this information is not
present, fault code 84 is generated.
Action: Check to see whether there are any fault codes stored
in the ABS control unit. Check connectors and wiring in the
communications circuit.

cardiagn.com
Fault: Impossible signal from throttle pedal kick-down
Fault code 85 switch.
Cause: Control unit has sensed a signal on pin 44, despite the
throttle pedal not being fully depressed.
Comment: The kick-down switch closes to earth (0V). If a
faulty analog value is received from the throttle pedal sensor,
fault code 76 is generated, but the control unit cannot then
generate fault code 85.
Action: Check whether there are any fault codes stored in the
EDC control unit and if the Opticruise control unit has stored
fault code 76. Check the kick-down switch in the throttle
pedal sensor, connectors and wiring.

50 © Scania CV AB 1995 05:05-02 en

 Fault codes

Fault: Incorrect gear ratio in gearbox.

Fault code 86
Cause: The relationship between the speed of the input shaft
and output shaft does not correspond to the gear engaged.
Comment: Input shaft speed is taken from the engine speed
sensor. This means that the clutch must be fully released for
speed comparisons to be made.
This fault code can be generated if the control unit has
received confirmation that the clutch is released, but it is still
slipping. The fault code can also be generated if there are
faulty confirmation signals for gear position.
Action: Check if fault codes for gear positions or road speed
sensors are stored. Check that the control unit is configured
for the correct type of gearbox.

cardiagn.com
Fault: Impossible deviation, vehicle speed compared to speed
Fault code 87 signal from ABS.
Cause: Control unit has sensed too great a difference in fre-
quency between the signals to pins 31 and 49 (which together
generate a frequency in the control unit) and the signal to pins
20 and 38.
Comment: The difference between the signal from the induc-
tive speed sensor on the gearbox output shaft and the speed
signal from the ABS control unit was greater than permitted.
Action: Check the road speed sensor on the gearbox output
shaft, fault codes in the ABS system, connectors and wiring.

05:05-02 en © Scania CV AB 1995 51

 Fault: Impossible deviation, tachograph compared to speed
Fault code 88 signal from ABS.
Cause: The control unit has sensed that the difference in fre-
quency between the signals to pin 32 and the signal to pin 20
and 38 was too great.
Comment: The difference between the signal from the tacho-
graph and the speed signal from the ABS control unit was
greater than permitted.
Action: Check the tachograph, fault codes in the ABS system,
connectors and wiring.

cardiagn.com
Fault: ABS cannot provide a reliable value for vehicle speed.
Fault code 89
Cause: The control unit has received a message from ABS via
the communications circuit (pins 20 and 38) that shows that
the speed value is impossible.
Comment: In this case, the fault is unlikely to lie with the
communications circuit. Otherwise, the control unit should
have generated another code (fault code 82 or 84).
Action: Check whether there are any fault codes stored in the
ABS control unit.

52 © Scania CV AB 1995 05:05-02 en

 Electrical system

Electrical system

References to wiring diagrams

At the time of going to press, no wiring diagrams for the particu-
lar fault codes have been produced. We therefore refer to the
connection diagram in Group 16 of the Workshop Manual.

Connection diagram

cardiagn.com
Publication number: 16:04-21.

Circuit diagrams
Publication number: No information.

Control unit configuration

Configuration is briefly covered on page 11.

Location of electrical components.

See overleaf.

05:05-02 en © Scania CV AB 1995 53

Electrical system

Location of electrical Item Function

components
B16 Reversing lights
B25 Throttle actuation1 (included in D35)
B26 Kick-down (included in D35)
B27 Clutch pedal fully depressed

B41 Confirmation, high range

B42 Confirmation, low range
B43 Confirmation, high split
B44 Confirmation, low split

B49 Exhaust brake and engine brake program

C46-
C401 Connector

D18 Diode unit for EDC

D35 Throttle pedal sensor
E5 Control unit, Opticruise

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E6 Hall effect sensor
E12 Control unit, EDC
F2 Fuse holder
G4 Earth connection, instrument panel

G8 Earth connection, instrument panel

G13 Earth connection, connector panel
G18 Earth connection, connector panel
O1 Instrument cluster

O4 Tachograph
P2 Central electric unit
S17 Exhaust brake (on instrument panel)
S30 Power take-off,EG
(S31) Power take-off, EK/ED

S88 Diagnostics switch

S100 Program selector
S101 Driving mode selector
T17 Speed sensor, output shaft
T20 Speed sensor, for tachograph

V13 Solenoid valve, EG power take-off

V20 Solenoid valve, right lateral stroke
V21 Solenoid valve, left lateral stroke
V22 Solenoid valve, neutral position
V23 Solenoid valve, rearward longitudinal stroke
V24 Solenoid valve, forward longitudinal stroke
V62 Solenoid valve, low split
V63 Solenoid valve, low range
V77 Solenoid valve, high split
V78 Solenoid valve, high range

1. This switch is not used for the actual Opticruise system.

It closes at the start of throttle pedal travel.

54 © Scania CV AB 1995 05:05-02 en

05:05-02 en

cardiagn.com
©
Scania CV AB 1995

100917

Electrical system
This figure applies to both LHD and RHD vehicles and covers all
affected optional equipment. Vehicles with less optional equipment
are covered where appropriate.
55
56

Electrical system
The tables on this spread show which input signals the control unit can receive.

Input signals
Input signals
Function Source Signal type Pin
Confirmation of low split Confirmation switch, split +24V UX 4
Confirmation of high range Confirmation switch, range +24V UX 5
Confirmation of rearward longitudinal Hall effect sensor +18V (supplied from UX) 6
stroke
Confirmation of neutral position Hall effect sensor +18V (supplied from UX) 7
Gives clutch pedal position Lower pedal switch Earthing (0V) 8

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Shows whether EK/ED power take-off Switch +24V 9
is activated
©
Scania CV AB 1995

Request for upshift Driving mode selector +24V UX 10

Request for neutral position Driving mode selector +24V UX 11
Activation of ”Hill” program Program selector +24V UX 12
Confirmation of high split Confirmation switch, split +24V UX 23

Confirmation of right-hand lateral Hall effect sensor +18V (supplied from UX) 24
stroke
Activates engine brake program Retarder control unit or floor switch +24V 27
To request down shift Driving mode selector +24V UX 28
To request automatic position Driving mode selector +24V UX 29
05:05-02 en
05:05-02 en

Input signals, contd.

Function Source Signal type Pin
To activate the test program Diagnostics switch Earthing (0V) 30
Gives vehicle speed Sensor on output shaft Frequency 31
Gives vehicle speed Tachograph Frequency 32
Confirmation, low range Confirmation switch, range +24V UX 41

level, length of cables and the condition of cables and contacts.

Stated readings can vary due to a number of factors such as battery voltage
Confirms left-hand lateral stroke Hall effect sensor +18V (supplied from UX) 42

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Confirms forward longitudinal stroke Hall effect sensor +18V (supplied from UX) 43
To request kick-down Kick-down switch Earthing (0V) 44
©

Gives clutch pedal position Upper pedal switch Earthing (0V) 45

Scania CV AB 1995

To request manual position Driving mode selector +24V UX 47

To request reverse position Driving mode selector +24V UX 48

Gives vehicle speed Sensor on output shaft Frequency 49
Shows whether EG power take-off is Switch +24V 50
activated

Electrical system
57
58

Electrical system
The table below shows which output signals the control unit can supply.

Output signals
Output signals
Function Destination Signal type Pin
To request low split Solenoid valve, low split +24V 2
To request forward longitudinal stroke Solenoid valve, forward longitudi- +24V 3
nal stroke
Gives vehicle speed Retarder control unit via C56 Frequency (+24V) 14
To request right-hand lateral stroke Solenoid valve, right-hand lateral +24V 17
stroke
To request high split Solenoid valve, high split +24V 18

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To request rearward longitudinal stroke Solenoid valve, rearward longitudi- +24V 22
©

nal stroke
Scania CV AB 1995

To activate buzzer Buzzer Earthing (0V) 33

Provides power supply Sensor, controls, display +24V 36
To request low range Solenoid valve, low range +24V 39
To request neutral position Neutral solenoid valve +24V 40

To request activation or disconnection Exhaust brake control unit PWM Signal 52

of exhaust brake
To request left-hand lateral stroke Solenoid valve, left-hand lateral +24V 53
stroke
To request high range Solenoid valve, high range +24V 54
05:05-02 en
 lines etc.
The table below shows the control unit connections for power supply, system earth, communications

Other connections
05:05-02 en

Other connections
Function Source or destination Signal type Pin
Earth for control unit G13 Earthed (0V) 1
Power supply in From batteries, fuse 41 +24V (U30) 19
Communication EDC, ABS/TC etc Data 20
Communication Diagnostic socket for PC Data 25

Communication Diagnostic socket for PC Data 35

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Communication EDC, ABS/TC etc Data 38
Communication Digital display Data 51
©

Power supply in Via starter switch, fuse 5 +24V (U15) 55

Scania CV AB 1995

Electrical system
59
Electrical system

63
Driving mode selector - R + R 54

• The figure to the right shows the internal con- 53

nection of the driving mode selector when in - N + N 64
neutral position. 83
- A + A 84
• The lower figure shows which contacts are
closed when the driving mode selector is in 73
its various positions. - M + M 74

43
+ 44

33
- 34

Position Input pin (UX supply) Output pin

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33 43 53 63 73 83 34 44 64 54 74 84
R+

R-
R

R N

N+
N-

N A

A+

A-

A M

M+

M-

= Connection between each terminal pin

60 © Scania CV AB 1995 05:05-02 en
 Test program

Test program
• The vehicle must be stationary and the engine be switched off,
unless otherwise stated in the particular test stage.
• Power should be on (starter key to drive position)
• The test program is controlled using the diagnostic switch, con-
cealed under a cover on the instrument panel.

cardiagn.com
The test program consists of start, five test stages
and end. The test program only runs in one direc- FOOTCONT
tion, but can be repeated any number of times. The
diagnostic switch is used to proceed to the next
stage. HANDCONT
TESTING
The figure to the right shows the gear indicator dis- GEARENGA
play before each test stage. This is explained in
more detail in the table below. END TEST
ENGINCOM

RPM INFO
Various phases of test program
Display Intention of test

Various phases of test program

TESTING Test program starts. Presentation of chassis number and control unit part
numbers for hardware and software. Then any fault codes.
FOOTCONT Testing foot controls
HANDCONT Testing hand controls
GEARENGA Testing changing movements and confirmation signals
ENGINCOM Testing engine communication
RPM INFO Testing engine speed sensors and road speed sensors
END TEST Test program ended

05:05-02 en © Scania CV AB 1995 61

Test program

General
The test program should no be used when driv-
ing. Generally, the vehicle should be stationary,
with the engine switched off before testing
starts.

! WARNING!

The vehicle may only be driven with the

test program running when this is
demanded in the test instructions. Under
no other circumstances.

If the control unit registers a road speed or

engine speed during testing, the test program is
interrupted. The control unit then returns to nor-

cardiagn.com
mal operation. The intention of this is to avoid
END TEST
the danger of an unsuitable gear being engaged.
There are however two test stages which require
the vehicle to be driven and this is when road
speed or engine speed are to be checked. This is
explained in the particular test stages (RPM
INFO and ENGINCOM).

Text in display FOOTCONT HANDCONT

For each test stage, a ”heading” is shown in the
display. At the same time, the buzzer gives a GEARENGA
short signal. This reduces the danger of confus-
ing the various test stages. RPM INFO ENGINCOM

As the gear indicator display is limited to a cer-

E K
tain size, letters are used as symbols for the vari-
ous signals etc in the different test stages. These
symbols are explained in each test stage.

62 © Scania CV AB 1995 05:05-02 en

 Test program

TESTING Starting the test program

Fault codes are read at the beginning of the Opticruise test
program. This is also described on pages 16 and 17 in this
booklet. Here, the test program is described in full.

1 The vehicle should be stationary with the engine switched

off.
2 Switch on the power with the starter key. Wait for five
seconds and then press the diagnostic switch for at least
half a second. Release it. ”TESTING” appears in the dis-
play and the buzzer sounds.

Leave the diagnostic switch for the moment. The test pro-
ECU NO gram has now started. All parts of the display light for one
second. The buzzer sounds.

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PROG NO 3 ”ECU NO” is displayed, directly followed by the part
number of the control unit hardware.

CHASSNO 4 ”PROG NO” is displayed, directly followed by the part

number of the control unit software.

FCODES 5 ”CHASSNO” is displayed, directly followed by the vehi-

cle chassis number.
6 ”F CODES” is displayed, directly followed by any fault
codes stored. More on this below.
• The fault codes are displayed one at a time, with two sec-
onds between them.
• When all stored fault codes have been displayed, the
buzzer sounds briefly. The stored fault codes are then dis-
E010 003 played again. This may be repeated any number of times,
so there is no danger if you should lose concentration.

The display can, for example, look like the figure to the
A B left. A shows the number of the fault code (10 in this case)
and B shows how many times this fault code has been reg-
istered (3).
7 Note the fault codes. Proceed to the next test stage. See
next page.

05:05-02 en © Scania CV AB 1995 63

Test program

FOOTCONT Foot controls

The gearbox cannot be operated as long as the control unit is
occupied with this test stage.
1 Preconditions:Stationary vehicle, engine switched off and
power on.
2 Press the diagnostic switch for at least a half second and
release it. ”FOOTCONT” is displayed.
3 Test the controls in order. When each letter is displayed,
the particular signal is active. Use the table below for
clarification.

Signal designation

E Floor switch for engine brake program (and

exhaust brake)

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U Upper switch for clutch pedal

D Lower switch for clutch pedal

B Brake pedal switch

K Kick-down switch (integrated in throttle pedal sen-

sor)

4 When the test has ended, proceed to the next test stage.

64 © Scania CV AB 1995 05:05-02 en

 Test program

HANDCONT Hand controls

The gearbox cannot be operated as long as the control unit is
occupied with this test stage.
1 Preconditions:Stationary vehicle, engine switched off and
power on.
2 Press the diagnostic switch for at least one half second
and release it. ”HANDCONT” is displayed.
3 Test the controls in order. When each letter is displayed,
the particular signal is active. Use the table below for
clarification.

Signal designation

R Driving mode selector to reverse position

R

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N Driving mode selector to neutral position
N
A Driving mode selector to automatic position
A
M Driving mode selector to manual position
M
D Driving mode selector to downshift position
D
U Driving mode selector to upshift position
U
H Program selector for normal driving or for steep
H uphill slopes1

1 1 = Switch for power take-off (PTO EK/ED)

1 2 = Switch for power take-off (PTO EG)
2
X = Both power take-offs activated simultaneously
X
1/2/X 1. When the driving mode selector is set for steep uphill slopes,
the letter H should be displayed.

4 When the test has ended, set the driving mode selector to
neutral and proceed to the next test stage.

05:05-02 en © Scania CV AB 1995 65

Test program

GEARENGA Gear changing movements and confirmation

signals
In this case, we force the solenoid valves which release com-
pressed air for the shift cylinders and read the confirmation
signals. In this way, it is possible to check that each gear
changing cycle works properly.
If there are fault codes stored which indicate loss of or impos-
sible road speed signals, this test stage cannot be used for
safety reasons.
! WARNING!
1 Preconditions: Stationary vehicle, engine switched off,
Engine must be switched off compressed air in air system and power on.
during testing.
2 Press the diagnostic switch for at least half a second and
then release it. ”GEARENGA” is displayed.
3 Hold the clutch pedal depressed and try the positions of
the driving mode selector in turn. This is described on the

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following pages. Use the table below for clarification.

Signal designation

r Range confirmation, where L=low range, H=high

range and X=both low range and high range at the
same time

L Confirmation for left-hand lateral stroke

B Confirmation for rearward longitudinal stroke

Range gear position is
always displayed on the far
left of the display, as L, H or
N Confirmation for neutral position
X.
F Confirmation for forward longitudinal stroke

R Confirmation for right-hand lateral stroke

r s
s Split confirmation, where L=low split, H=high
split and X=both low split and high split simultane-
ously
Split gear position is always
displayed on the far right of
the display, as L, H or X. 4 When the test has ended, check that the gearbox is in neu-
tral and proceed to the next test stage.

66 © Scania CV AB 1995 05:05-02 en

 Test program

Low split and low range simultaneously

R
1 Set the driving mode selector as in fig. 1.
2 Check that LNL is displayed. N

High split and high range

simultaneously
R
3 Set the driving mode selector as in fig. 2.
4 Check that HNH is displayed. N

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A

Left lateral stroke

5 Set the driving mode selector as in fig. 3. R

6 Check that HLNH (or LLNL) is displayed. N

Rearward longitudinal stroke on

left-hand side R
7 Set driving mode selector as in fig. 4.
N
8 Check that HLBH (or LLBL) is displayed.
A

05:05-02 en © Scania CV AB 1995 67

Test program

Forward longitudinal stroke on left-hand

side R

9 Set driving mode selector as in fig. 5. N

10 Check that HLFH (or LLFL) is displayed.
A

Rearward longitudinal stroke in centre

position R

11 Set driving mode selector as in fig. 6.

N
12 Check that HBH (or LBL) is displayed.

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A

Forward longitudinal stroke in centre

position R
(Only applies to GR gearbox, not GRS)
N
13 Set driving mode selector as in fig. 7.
A
14 Check that HFH (or LFL) is displayed.
M

Rearward longitudinal stroke on

left-hand side R
15 Set driving mode selector as in fig. 8.
N
16 Check that HBRH (or LBRL) is displayed.
A

68 © Scania CV AB 1995 05:05-02 en

 Test program

Forward longitudinal stroke on

right-hand side R

17 Set driving mode selector as in fig. 9.

N
18 Check that HFRH (or LFRL) is displayed.
A

Neutral position
Neutral position often, but not always, arises in R
combination with another confirmation signal.
N
19 Set driving mode selector as in fig. 10.

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20 Check that HLNH (or LLNL) is displayed. A

10

21 Set driving mode selector as in fig. 11.

R
22 Check that HNH (or LNL) is displayed.
N

11

23 Set driving mode selector as in fig. 12.

R
24 Check that HNRH (or LNRL) is displayed.
N

12

05:05-02 en © Scania CV AB 1995 69

Test program

ENGINCOM Engine communication

In this test stage, we check the kind of data that Opticruise
must have from the EDC system. In this way, it is possible to
check whether sensors, EDC control unit data processing and
the actual communications circuit are working properly.
During this test, the display gives the test result instead of
gear position and the like. In addition, the vehicle can be
driven as normal.
1 Preconditions: Initially stationary vehicle, engine
switched off and power on. The vehicle should be driven
when the actual test stage has been initiated.
2 Press the diagnostic switch for at least one half second
and release it. ”ENGINCOM” is displayed.
3 Start the engine and drive the vehicle. Drive at an even
speed and check that the values displayed seen plausible.

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Use the table below for clarification.

Signal designation

gg Requested throttle as percentage of full throttle (0 -

gg 99 %)

Requested throttle ee Actual torque (x 100 Nm)

dd Requested torque (x 100 Nm)

ee tt Engine temperature (0 - 99 ˚C)

Actual torque 4 When the test has ended, proceed to the next test stage.

dd

Requested torque

tt

Engine temperature

70 © Scania CV AB 1995 05:05-02 en

 Test program

RPM INFO Speed sensors

Here, we check the various speed information which is com-
pared by Opticruise. In this way, it is possible to check that
both sensors and their wiring are working properly.
During this test, the display gives the test result instead of
gear position and the like. In addition, the vehicle can be
driven as normal.
1 Preconditions: The vehicle should be driven when the
actual test stage has been started.
2 Press the diagnostic switch for at least one half second
and release it. ”RPM INFO” is displayed.
3 Drive the vehicle at an even speed and check that the val-
ues displayed seem plausible. Use the table below for
clarification

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Signal designation

nn Engine speed (x 100 rpm)

nn
v_1 Propeller shaft speed from sensor on gearbox out-
Engine speed put shaft (x 10 rpm)

v_2 Speed signal from tachograph, recalculated to pro-

peller shaft speed (x 10 rpm)

v_1 4 When the test has ended, press the diagnostic switch to
end the test program. When this has been done, ”END
Propeller shaft speed TEST” is displayed and the control unit returns to normal
operation.

See pages 16 to 17 for description of any fault messages

which have arisen during test driving.

v_2
From tachograph

05:05-02 en © Scania CV AB 1995 71

 cardiagn.com

72 © Scania CV AB 1995 05:05-02 en

 Mechanical work

Mechanical work

General
Internally, the gearbox is standard. Its operating system is similar
to the corresponding one for 3 series CAG 2, but with the differ-
ence that the stroke damper for Opticruise is now built into the
longitudinal stroke cylinder. The gearshift housing, located on
the top of the gearbox is also changed. The design is more com-
pact than in previous models.

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Hall effect sensor and shift cylinders
Mechanically, Opticruise has no great changes. We therefore
concentrate on changing and setting the hall effect sensor and
changing the shift cylinders. This is described on the following
pages.

Confirmation switches
The four confirmation switches are of the same type; normally
closed. Tightening torque: 20 Nm. Their location is shown in the
figure below, with the gearbox shown viewed from above. On
older gearboxes, B42 is located on the right-hand side. Designa-
tions are explained on page 54.

B44

B42
100870

B43 B41
05:05-02 en © Scania CV AB 1995 73
Mechanical work

Hall effect sensor, adjusting and

replacement
Use the control unit’s integrated test program or
a PC to detect faults in the hall effect sensor, and
to verify that faults have been corrected when a
repair is completed.

Removal
1 Set the driving mode selector to the neutral
position.
2 Detach the air hoses from the longitudinal
stroke cylinders and the lateral stroke cylin- ABA = B
ders. Unplug the connector to the hall effect
sensor wiring from the sensor housing.
3 Detach the gearshift housing from the gear-
box and place it upside down on the work-

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bench.
4 Detach the sensor housing from the gear-
shift housing.
5 Blow compressed air into the centre air con-
nection on the longitudinal stroke cylinder.
This sets the gear shift shaft to the neutral
position. Check that the stop on the lever is
in the centre of the coulisse as in the figure
above to the right.

Checking and adjusting

6 Remove both the guide pins from guide
plate 99 150 (these are not needed). Fit the
guide plate in the place of the sensor hous-
ing. Check that the magnet housing is in the
correct position.
7 When adjusting: Undo the magnet housing
bolts enough to move the housing, but no
further.
Note: The bolts are locked with locking com-
pound, but do not heat the magnet housing. This
may damage the magnet.
8 Adjust the position of the magnet housing
using the guide plate. Then lock the bolts 1 Sensor housing
with locking compound 561 029 and screw 2 Magnet housing
then fully down. 3 Spring pins
Continued > 4 Guide plate 99 150
(Figure shows series 3 design)

74 © Scania CV AB 1995 05:05-02 en

 Mechanical work

Hall effect sensor, fitting

9 Fit the sensor housing to the gear shift hous-
ing.
Refit the gear shift housing to the gearbox.

Changing the longitudinal stroke

cylinder
The vehicle’s compressed air system must be
pressurized for the longitudinal stroke cylinder
to be set to the correct position before it is
removed.
1 Switch on the power. Set the driving mode
selector to neutral. The longitudinal stroke
cylinder is set to neutral.

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2 Cut the power. Disconnect the three air
hoses from the longitudinal stroke cylinder.
3 Undo the four securing bolts and remove the
cylinder.
4 Fit the new cylinder. Blow compressed air
into the centre connector, setting the cylin-
der to the neutral position. Make sure that
teeth on the gearshift shaft are engaged in
the centre position.

05_5336
5 Fit the air hoses.
6 Remove the level plug. Fill with ATF fluid
up to the hole (about 0.27 litres).
7 Switch on the power and check the gear
changing movements using the test program
(test stage ”GEARENGA”).
The longitudinal stroke cylinder can be turned if
extra space is required. If this is done, the com-
pressed air couplings must also be switched.
Hint: Remove the gear selector housing from
the gearbox if turning the cylinder. this makes
the task easier.

05:05-02 en © Scania CV AB 1995 75

Mechanical work

Changing the lateral stroke

cylinder
It is not necessary for the compressed air system
to be pressurized in order to remove the lateral
stroke cylinder.
1 Switch on the power. Set the driving mode
selector to neutral position.
2 Cut the power. Disconnect the hoses from
the lateral stroke cylinder.
3 Undo the securing bolts and remove the cyl-
inder.
4 Lubricate the piston with brake grease, part
No. 319 308.
5 Fit the new cylinder.

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6 Fit the air hoses.
7 Switch on the power and check the gear

05_5334
changing movements using the test program
(test stage ”GEARENGA”).

Location of compressed air

cylinders
• The figure to the right shows which solenoid V23
valve the various compressed air couplings V22
belong to. V20
V24 V21
• The figure applies to standard vehicle ver-
sions.
• The longitudinal stroke cylinder can be
turned. This is sometimes necessary to allow
sufficient clearance for e.g. a hydraulic
pump.
V62
If this is the case, the air lines for V23 and V77
V24 must be swapped. This allows the longi-
tudinal stroke cylinder to work in the right
direction when it has been turned.

V63
100859

V78

76 © Scania CV AB 1995 05:05-02 en

 Exploded view drawings

Exploded view drawings

This chapter shows the exploded view drawings for the

most important Opticruise components on the gearbox.
Part numbers are given in our spare parts catalogues.
The drawing below shows the location of solenoid
valves for Opticruise. Designations are explained on
page 54. The location of air lines is shown on page 76.

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V23 V22 V24 V20 V21
100860

V63 V78 V62 V77 PTO

Location of solenoid valves on gearbox. The two

PTO solenoid valves are for the power take-offs.

05:05-02 en © Scania CV AB 1995 77

Exploded view drawings

Longitudinal stroke Item Quantity Designation

cylinder
1 1 Gasket
2 4 Screw
3 1 Housing
4 1 End plate

5 1 Gasket
6 5 Screw
7 2 Spring pin
8 2 Plug

9 2 Gasket
10 1 Piston rod
11 1 Rack
12 2 Retaining ring

13 2 Retaining ring
14 1 Piston rod
15 2 Washer

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16 2 Piston

17 4 Retaining ring
18 1 Bearing sleeve
19 1 V-ring
20 2 Bearing

21 1 O-ring
22 2 Piston
23 2 O-ring
24 2 Washer

25 2 Retaining ring
26 2 Seal
27 1 O-ring
28 1 Cylinder cover
29 3 Screw

78 © Scania CV AB 1995 05:05-02 en

 Exploded view drawings

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100918

Component parts of the longitudinal

stroke cylinder. Part numbers are listed
in our spare parts catalogues.
Remember to swap the compressed air
couplings if it is necessary to turn the
cylinder to increase available space.

05:05-02 en © Scania CV AB 1995 79

Exploded view drawings

Gear shift housing with Item Quantity Designation

lateral stroke cylinder
1 4 Bushing
2 1 Retaining ring
3 1 Filter disc for venting
4 1 O-ring

5 1 Sensor housing assembly

6 1 Magnet housing
7 1 O-ring
8 2 Spring pin

9 4 Screw
10 4 Screw
11 1 Gear shift shaft
12 1 Magnet holder

13 1 Screw
14 3 Screw
15 1 Lever

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16 2 Screw

17 2 Key
18 2 Spacer
19 1 Coulisse
20 2 Cap

21 4 Screw
22 2 Retaining ring
23 2 Washer
24 1 Spring

25 1 Spacer
26 1 O-ring
27 1 Retaining ring
28 1 V-ring

29 1 Lever
30 1 Cylinder
31 1 Piston
32 1 Spacer

33 1 V-ring
34 1 O-ring
35 1 O-ring
36 1 O-ring

37 1 O-ring
38 2 Screw
39 2 Plug
40 2 Gasket

41 1 Housing
42 1 Screw
43 1 Washer

80 © Scania CV AB 1995 05:05-02 en

 Exploded view drawings

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Component parts of the gear shift hous-
ing and lateral stroke cylinder. Part
numbers are listed in our spare parts
catalogues.

05:05-02 en © Scania CV AB 1995 81

Exploded view drawings

Compressed air parts Item Quantity Designation

on gearbox
1 1 Bracket
2 2 Bracket 1
3 3 Holder
4 2 Nut

5 2 Screw
6 2 Screw
7 2 Nut
8 11 Strap

9 22 Screw
10 22 Washer
11 7 Screw
12 7 Nut

13 14 Cone
14 9 Solenoid valve 2
15 7 O-ring

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16 2 Union

17 10 Elbow union
18 5 Elbow union
19 4 Union
20 1 Clip

21 1 Screw
22 4 Bracket
23 2 T-union

VAE M3 Plastic pipe

VAJ -”- Plastic pipe
VAF -”- Plastic pipe
VSR -”- Plastic pipe

VSS -”- Plastic pipe

XBN -”- Plastic pipe
VRH -”- Plastic pipe
VRL -”- Plastic pipe

VCH -”- Plastic pipe

VCL -”- Plastic pipe
VSH -”- Plastic pipe
VSL -”- Plastic pipe

A ERF 4 Union nut

Ferrule
Insert sleeve

1. Drawing shows early version

2. See page 77 for locations
3. M = By the metre
4. ERF = Whatever quantity is required

82 © Scania CV AB 1995 05:05-02 en

 Exploded view drawings

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Compressed air parts on gearbox. Part
numbers are listed in our spare parts
catalogues.

05:05-02 en © Scania CV AB 1995 83

 cardiagn.com

84 © Scania CV AB 1995 05:05-02 en